Conductive adhesive, and circuit board and electronic component module using the same

A conductive adhesive comprising:

• 10 to 90 wt % of Sn—Bi system solder powder and;
• the remainder of an adhesive containing organic acid, wherein
• the Sn—Bi system solder powder is composed of solder particles having a particle size L1 of 20 to 30 μm and solder particles having a particle size L2 of 8 to 12 μm, and
• a mixing ratio of the Sn—Bi system solder powder is such that the solder particles having a particle size of 20 to 30 μm occupy 60 to 80 wt % with respect to the whole solder powder, and the remainder is occupied by solder particles having a particle size of 8 to 12 μm.

A conductive adhesive comprising:

• 10 to 90 wt % of Sn—Bi system solder powder and;
• the remainder of an adhesive containing organic acid, wherein
• the Sn—Bi system solder powder is composed of solder particles having a particle size L1 of 20 to 30 μm and solder particles having a particle size L2 of 8 to 12 μm,
• a mixing ratio of the Sn—Bi system solder powder is such that the solder particles having a particle size of 20 to 30 μm occupy 60 to 80 wt % with respect to the whole solder powder, and the remainder is occupied by solder particles having a particle size of 8 to 12 μm,
• the adhesive containing organic acid is composed of at least an epoxy resin, a curing agent, the organic acid, and a thicking agent,
• the organic acid includes adipic acid and glutaric acid, and
• a ratio between the adipic acid and the glutaric acid is such that the adipic acid occupies 20 to 40 wt % of the whole organic acid, and the remainder is occupied by the glutaric acid.